HDD, Duckbill Valve and Air Valve

[sunami]

I have 3 questions and wonder if someone here can help:

1. I need to lay a sewage rising main in a winding footpath. Can HDD adopt a meandering alignment from one single drill pit?
2. What is typically the head loss coefficient of a Rubber Flex Slip-In In-Line Duckbill Check Valve and a Low Head Loss In-Line Duckbill Check Valve?
3. When pumping past an air valve, is it required to ensure there is at least a 1m head above the air valve, rather than measuring from the invert level of the pipe? I'm particularly curious about how this applies when dealing with larger pipes, such as those with a diameter of 1m or more. What’s the best practice for ensuring proper operation in these cases?

Thanks.

 

[coloeng]

Answer to Question 1: Yes, HDD can do a meandering path from one drill pit. A caveat is that the degree of meander is controlled by the diameter of the drill rod. Additionally, the more meanders the higher resistance to pull-back on the pipe and the larger machine that is required, which in turn can increase the diameter of the drill pipe. You should contact an HDD contractor that specializes in this type of construction.

 

[sunami]

Answer to Question 1: Yes, HDD can do a meandering path from one drill pit. A caveat is that the degree of meander is controlled by the diameter of the drill rod. Additionally, the more meanders the higher resistance to pull-back on the pipe and the larger machine that is required, which in turn can increase the diameter of the drill pipe. You should contact an HDD contractor that specializes in this type of construction.

Thanks.

 

[bimr]

2. Contact the manufacturer. https://www.cla-val.com/waterworks/rubber-flex-duckbill-check-valves

3. For an air release valve, depending on the specific design, the minimum sealing pressure can be as low as around 0.2 bar, allowing it to seal effectively even in low-pressure situations within a piping system; however, the exact minimum pressure will vary depending on the valve manufacturer and application.